<template>
    <el-container class="home_container">
        <!-- 头部区域 -->
        <el-header>
            <div>
                <img src="../assets/heima.png" alt="">
                <span>电商后台管理系统</span>
            </div>
            <el-button type="info" @click="logout">退出</el-button>
            </el-header>
        <!-- 页面主体区域 -->
        <el-container>
            <!-- 侧边栏 -->
            <el-aside :width="isCollapse ? '64px': '200px'">
                <div class="toggle-button" @click="toggleCollapse">|||</div>
                <!-- 侧边栏菜单区域 -->
                <el-menu background-color="#333744" text-color="#fff" 
                active-text-color="#409eff" unique-opened :collapse="isCollapse"
                :collapse-transition="false" :router="true" :default-active="activePath">
                <!-- 一级菜单 -->
                <el-submenu :index="item.id + ''" v-for="item in menuList" :key="item.id">
                    <!-- 一级菜单的模板 -->
                    <template slot="title">
                        <i :class="iconsObj[item.id]"></i>
                        <span>{{ item.authName }}</span>
                    </template>
                    <!-- 二级菜单 -->
                    <el-menu-item :index="'/' + subItem.path" v-for="subItem in item.children" 
                    :key="subItem.id" @click="saveNavState('/' + subItem.path)">
                        <template slot="title">
                            <i class="el-icon-menu"></i>
                            <span>{{ subItem.authName }}</span>
                        </template>
                    </el-menu-item>
                </el-submenu>
                </el-menu>
            </el-aside>
            <!-- 右侧主体内容 -->
            <el-main>
                <router-view></router-view>
            </el-main>
        </el-container>
    </el-container>
</template>

<script>
export default {
    data() {
        return {
            // 左侧菜单数据
            menuList: [],
            iconsObj: {
                '125' : 'iconfont icon-user',
                '103' : 'iconfont icon-tijikongjian',
                '101' : 'iconfont icon-shangpin',
                '102' : 'iconfont icon-danju',
                '145' : 'iconfont icon-baobiao'                
            },
            // 是否折叠，默认不折叠
            isCollapse: false,
            // 被激活的链接地址
            activePath: ''
        }
    },
    created() {
        this.getMenuList()
        this.activePath = window.sessionStorage.getItem('saveNavState')
    },
    methods: {
        logout() {
            window.sessionStorage.clear()
            this.$router.push('/login')
        },
        // 获取所有菜单
        async getMenuList() {
            const {data : res} = await this.$http.get('menus')
            if(res.meta.status !== 200) return this.$message.error(res.meta.msg)
            this.menuList = res.data
            // console.log(res)
        },
        // 点击按钮，切换菜单的折叠与展开
        toggleCollapse() {
            this.isCollapse = !this.isCollapse
        },
        // 保存链接的激活状态
        saveNavState(activePath) {
            window.sessionStorage.setItem('activePath', activePath)
            this.activePath = activePath
        }
    }
}
</script>

<style lang="less" scoped>
    .home_container {
        height: 100%;
    }

    .el-header {
        background-color: #373d41;
        display: flex;
        justify-content: space-between;
        padding-left: 0;
        align-items: center;
        color: #fff;
        font-size: 20px;
        > div {
            display: flex;
            align-items: center;
            span {
                padding-left: 15px;
            }
        }
    }

    .el-aside {
        background-color: #333744;
        .el-menu {
            border-right: none;
        }
    }

    .el-main {
        background-color: #eaedf1;
    }

    .iconfont {
        margin-right: 10px;
    }

    .toggle-button {
        background-color: #4a5064;
        font-size: 10px;
        line-height: 24px;
        color: #fff;
        text-align: center;
        letter-spacing: 0.2em;
        cursor: pointer;
    }
</style>
